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Title:Outstanding problems in nonequilibrium statistical physics
Authors:Faggian, Marco (Author)
Ginelli, Francesco (Mentor) More about this co-author... New window
Levnajić, Zoran (Co-mentor)
Language:Slovenian
Work type:Doctoral dissertation
Tipology:2.08 - Doctoral Dissertation
Organization:FIŠ - Faculty of Information Studies in Novo mesto
Abstract:This PhD thesis is mainly devoted to the study of different problems in nonequilibrium systems that undergo certain phase transitions. The first part of this thesis constitutes a brief review of fundamental concepts in statistical physics. Many of them, of course, will be useful in the remaining of the thesis. My research is thus articulated in three main chapters. The second chapter focuses on a numerical and experimental evidence of an absorbing phase transition, so far associated with spatiotemporal dynamics provided in a purely temporal optical system. We provide a numerical and experimental study of an effective model for a bistable semiconductor laser, with long-delayed opto-electronic feedback and multiplicative noise showing the peculiar features of a critical phenomenon belonging to the directed percolation universality class. In the third part of the thesis we present a random network of heterogeneous phase oscillators in which the links mediating the interactions are constantly rearranged with a characteristic timescale and an extremely low instantaneous connectivity. We will show that, provided strong coupling and fast enough rewiring are considered, the network is able to reach partial synchronisation even in the vanishing connectivity limit. The last part is dedicated to a systematic test of an effective thermodynamics approach proposed for the identification of critical phase transitions in nonequilibrium systems by making a formal analogy with equilibrium systems. When the authors apply it to experimental data of neurons, this method seems to bring a signature of a "special critical point". However, the approach has never been tested on synthetic data and for this reason we will test it on out of equilibrium toy models that display critical transition in a known range of parameters. In the concluding section I summarise and briefly comment my main results and sketch some directions for further research.
Keywords:statistična fizika, ravnotežna statistična fizika, neenakomerna statistična fizika, termodinamika, kritični pojavi, kritična točka, Kuramoto model, skupina za renormalizacijo, samoorganizirana kritičnost omrežja, Zipfov zakon, efektivni termodinamični pristop
Year of publishing:2019
Publisher:[M. Faggian]
Source:Novo mesto
COBISS_ID:2048583955 Link is opened in a new window
UDC:536.9(043.2)
Views:2535
Downloads:155
Files:.pdf DR_2019_Marco_Faggian.pdf (14,36 MB)
 
Metadata:XML RDF-CHPDL DC-XML DC-RDF
Licenca:Priznanje avtorstva-Nekomercialno-Brez predelav Novo okno
  
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